1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a backlight unit capable of preventing noise and a liquid crystal display using the same.
2. Discussion of the Related Art
Generally, a liquid crystal display displays desired images by controlling the transmittance of light emitted by a backlight unit.
Backlight units are classified into edge-type backlight units and direct-type backlight units depending on the positions of lamps. Edge-type backlight units are mainly used for small-size liquid crystal displays such as notebooks and direct-type backlight units are mainly used for large-size liquid crystal displays such as televisions.
Direct-type backlight units require a large number of lamps for high and uniform luminance. To achieve cost reduction and drive reliability, recent direct-type backlight units use External Electrode Fluorescent Lamps (EEFLS) which can be driven in parallel by a single inverter. External electrodes are formed at both ends of each EEFL. Thus, to achieve parallel driving, the direct-type backlight unit includes a plurality of common lines for supplying lamp drive voltages and a plurality of sockets for fixing the lamps in order to connect the external electrodes of the lamps in parallel.
Conventional direct-type backlight units have a plurality of molded substrates for fixing sockets and common lines. The sockets are fixed to the molded substrates using individual screws. Wires for supplying lamp drive voltages are also fixed to ends of the molded substrates using individual screws, such that the wires are connected to the common lines, and the inverter unit is then connected to the wires outside the backlight unit. The molded substrates with the sockets and common lines fixed thereto are fixed to a bottom case using the same method.
The sockets and common lines, which are fixed to the plurality of molded substrates using screws in the above manner, produce noise due to vibration caused by voltages supplied thereto and thermal expansion thereof. In addition, fixing the sockets to the molded substrate using individual screws increases assembly time and costs. Further, connecting the wires for supplying lamp drive voltages to the inverter unit outside the backlight unit complicates arrangement of wires and increases the volume of the liquid crystal display.